I have a server that the team foundation server is installed on. I can connect to TFS from several computers, but I can't connect to its from my laptop through internet. I can connect to it from web, but I can't via team explorer.

Indeed I can't add server via team explorer in visual studio, and I receive following error.

I have connected to this server for 3 months. Then I deleted the team project from server and worked offline. Now I want to add my solution to TFS, but I can't connect to it.